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Message Posted: Wed, 03 Dec 2003 @ 12:51:13 GMT


     
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Subj:   Re: Fastload Acquisition Phase
 
From:   Anomy Anom

<-- Anonymously Posted: Wednesday, December 03, 2003 07:38 -->

  Yes.. I understand that it does transfer the data in blocks.. But when it transfers to the AMPs, how would it know, which block to go to which AMP..? Some hashing principle should be there for distributing the block of rows into the different AMPs, I guess..  



FastLoad simply sends those blocks (up to 64 KB each in current versions) in round robin fashion to each AMP in the system, using all sessions as David explained. Then each AMP must deblock the records, apply the hashing algorithm to proper field in each record, and create new blocks in memory buffers for each other AMP in the configuration. When every such block is full it is sent to proper destination AMP using a monocast message over the BYNETs. After last block is sent by FastLoad all partial buffers in each AMP are sent to corresponding AMPs, and every AMP finally has all records that belong to it, according to hashing on the field which corresponds to Primary Index for the table being loaded. Then AMPs are ready for Phase 2.


Best regards.



     
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